Multi-thread File Downloader

Author by Anusid Wachiracharoenwong (@ttxking)

Description :

an UI application that downloads file from URL. It uses multiple threads to download parts of a file in parallel. This helps you speed up your downloads. If the file is larger than 50MB (52,428,800 bytes in binary) it will use 5 threads. Otherwise, it will use 1 thread

Main Features

• URL TextField - UI for the user to enter the URL
• Download Button - the user click on this button to download
• Cancel Button - the user click on this button to cancel download
• ProgressBar - this progress bar show overall download progress of the program
• SubProgressBar - these 5 progress bars shows the progress of each thread

Usage

1. When you start the program

   • Enter URL
   • Click Download Button

   

2. After click Download Button

   • enter the file name (the default file name is from URL)
   • choose directory to put the file (initial directory is user.home)
   • click save

   

3. After selected file destination

   • the program will start downloading
   • the progressbar will update the process of the download

   If the file is more than 50MB it will use 5 threads Otherwise it will use one thread

4. After the download is complete

   • Status Label will show "Download Completed"
   • You can see the time used in the terminal

   

   Extra

   • Cancel the download - when the user click cancel all tasks will stop and also the progressBar. The Label will show "Cancelled".

   

   • Invalid URL - when the user enters non-URL text , the program will prompt an error

   

   • Clear - when the users click on this buttons , the text field will be cleared. The Status Label will be "status" and the progress bar will become 5 as defaults

   

How to run .jar file

Verify that your Jar file is runnable by running it yourself.

The command is :

java -jar flashget.jar 

For Java 11 you need to specify the module path for JavaFX.

Enter:

java --module-path /path/to/javafx11/lib/ --add-modules javafx.controls,javafx.fxml,javafx.graphics -jar flashget.jar

Educational Value

1. How to use threads
2. Connect to a URL in Java
3. Design a JavaFX and using Scene Builder
4. Read from a URL , get the size of file from a URL and write the content to a file
5. Using RandomAccessFile class to go to any location in a file and then write (or read) starting at that location.

Technology Used

• JavaFX11
• Scene Builder
• HTTP connection
• JDK 11.0.5

Design Pattern

• Observer Pattern => in DownloadExecutor class

UML Diagram